With the development of mobile communication technologies, in order to realize the reuse of spectrum resources for different geographic locations, telecom operators lay more and more low-power nodes, so as to provide higher data rate for a user equipment (UE). When there are not much users near a low-power nodes, these low-power nodes may increase the coverage to cover distant UEs, in this way, the utilization of these low power nodes can be increased, and the cost of the network distribution can be reduced.
Currently, in the 3rd generation partnership project (3GPP) long term evolution system, in order to realize the transmission of the downlink control information and the downlink service data, the following are set up in the downlink physical channel: a synchronization signal, a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid automatic repeat request channel (PHICH), a physical downlink control channel (PDCCH), a physical downlink shared channel (PDSCH) and pilot signals, and etc. A user equipment synchronizes with an eNB by detecting the synchronization signals, where the synchronization signals are periodic signals, and the synchronization time may be extended, so that the synchronization signal can cover more distant UEs.
In the conventional LTE system, when the downlink bandwidth is 10 MHz, the downlink transmit power of an evolved base station eNB is 46 dBm, and the maximum uplink transmit power of a UE is 23 dBm. Therefore, the uplink coverage and the downlink coverage are substantially the same. For a low power node, the downlink transmit power of the low power node and the maximum uplink transmit power of a UE are both 23 dBm, which makes the downlink coverage area much smaller than the uplink coverage area. So, in the prior art, the downlink coverage area of the low power node is small, therefore, the more distant UEs cannot be covered.